1. Field of the Invention
The invention relates generally to cabinets and, more particularly, to a simple cabinet frame structure for housing electrical and electronic equipment and the like.
2. Description of Related Art
Many cabinet configurations for containing and protecting electrical assemblies have been developed in the last half century to house everything from complex vacuum tubes and other easily damaged components of the past to state of the art compact high speed hybrid circuits. Today electronic and electrical assemblies differ as to the space and proportions necessary to house them. While a cabinet the size of several refrigerators may be necessary to house a complex high voltage switching system, a cabinet the size of a phone book may be needed to house a more compact electrical arrangement. Although many cabinet structures have evolved, a basic cabinet frame structure that provides strength, ease of assembly, interchangeable simple parts in both a large or small structure, has yet to be realized.
A number of attempts have been made to provide a cabinet which satisfies these criteria, but typically either the cost or the complexity or both, and the size, versatility or strength has been less than desirable. By way of example, the following U.S. patents disclose either welded or modular frame assemblies representative of cabinet structures developed over the last 50 years:
U.S. Pat. No. 2,167,525: Rosendale PA0 U.S. Pat. No. 3,265,419: Durnbaugh et al. PA0 U.S. Pat. No. 3,182,846: La Kaff PA0 U.S. Pat. No. 3,919,603: Salvati et al.
The patents to Rosendale and Durnbaugh et al. both disclose welded cabinet structures. Rosendale employs gussets, triangular pieces of metal, welded in each corner to hold three mutually perpendicular struts in a corner arrangement. Durnbaugh et al. eliminates such gusset members and welds his strut members directly intersectingly together. However, each of their three strut members which form each corner have different end cross-sectional configurations and end profiles which complicates manufacture and construction of their frame. Additionally, four welds are desired to join the struts to create a rigid frame structure. The cabinet structures of Rosendale and Durnbaugh et al. therefore are very labor intensive.
The patents to La Kaff, and Salvati disclose cabinet configurations that involve mechanical assembly. In La Kaff, side frame struts are coupled to top and base members using engaging elements formed of generally rectangular aluminum blocks, which are attached by welding to the top and bottom members and struts. The engaging elements have frustoconical portions configured to fit snugly together. The top and base members are mated via the engaging elements, and bolted together. Both manufacturing costs and lack of versatility make this frame an undesirable alternative. Salvati et al. disclose a switch board frame assembly including a corner tie for supporting three structural corner members together. The corner tie has three perpendicular legs rectangularly shaped with three sides and outwardly facing flanges, the three struts being slid over the leg portions. However, the struts and leg portions have different cross-sectional configurations, and the corner tie is of a generally complex configuration, such that this frame structure is not conducive to low cost manufacturing techniques.
It would be an advancement in the art to provide a simple cabinet that eliminates the aforementioned disadvantages of the prior art.